To investigate the serum estrogenic activity of phyto-estrogens in healthy male volunteers, measured with the ER-CALUX assay after intake of soy nuts.
ID
Source
Brief title
Condition
- Endocrine disorders of gonadal function
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary endpoint of the study is the total serum estrogenic activity
measured with the ER-CALUX assay and expressed in estradiol equivalents (EEQs).
Secondary outcome
Information will be collected about background variables and potential
confounders, such as age, BMI, and consumed foodstuffs and potential
gastro-intestinal problems during the study.
Background summary
Soybeans and soy-based foodstuffs such as tofu contain high concentrations of
phyto-estrogens. Phyto-estrogens are structurally and functionally similar to
endogenous estrogens, which is why they are able to bind with the estrogen
receptor and exert agonistic or antagonistic effects. Previous studies showed
that a soy-rich diet may lead to high serum concentrations of genistein and
daidzein, the two main metabolites of phyto-estrogens. Whether this also
results in altered estrogenic activity is yet unknown. In the present study,
the effects of soy intake will be assessed using a new technique, the
Estrogen-Responsive - CALUX assay (ER-CALUX), which measures the total
estrogenic receptor activity in serum. With this assay, we attempt to elucidate
the biological relevance of phyto-estrogens that are present in soy-based
foodstuffs.
Study objective
To investigate the serum estrogenic activity of phyto-estrogens in healthy male
volunteers, measured with the ER-CALUX assay after intake of soy nuts.
Study design
In this explorative study, serum estrogenic activity will be measured at
variouspoints in time after intake of 50 grams of soy nuts by five of the six
participants. The first blood sample will be collected just before the
intervention, around 8:30 a.m. Subsequently, 4 blood samples will be taken at
three-hour intervals. The final blood sample is taken around 8:30 a.m. the next
morning. In order to get reference values, 6 blood samples are also drawn from
one participant who did not eat soy products.
Intervention
The intervention studied is a single intake of 50 grams of soy nuts, which are
available at a Herbalife reform shop and contain approximately 75 mgs of
phyto-estrogens, which corresponds with a traditional soy-rich diet.
Additionally, participants are not allowed to eat other soy-rich products in
the three days before and during the study.
Study burden and risks
Participants are unlikely to consider the intervention of soy nut intake to be
a burden. The burden consist mainly of the vena punction, which is repeated six
times within a period of 24 hours. The vena punction is performed by an
experienced research assistant and in close proximity of a medical doctor.
Postbus 9101
6500 HB Nijmegen
Nederland
Postbus 9101
6500 HB Nijmegen
Nederland
Listed location countries
Age
Inclusion criteria
- Healthy men
- Age 18 - 25
- BMI 18.5 - 25
Exclusion criteria
- use of anti-coagulants
- diagnosis diabetes, thyroid disorder or other chronic illness that potentially involves a disturbed endocrine system
- use of hormonal medication
- chronic kidney or liver disorder
- use of antibiotics three months before the experiment
- use of meat or dairy substitutes at least two times a week for the last six months
- soy allergy
- smoking
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
Register | ID |
---|---|
CCMO | NL11432.091.06 |